Category Labels (RFC) #13

Needs comments / suggestions on how to handle regex labels for commitlog.

Currently the categorization works in the following way.

Eg: a catg regex like so would produce the labels

$ commitlog g --categories="feat:,fix:"

## feat:
## fix: 

Though this doesn't make sense when you have really complex regex's handling the categorisation.

So, there needs to be a way to create labels for these category regexes

One possible way is to change the way the flags are parsed and have more than one instance of the flag.

$ commitlog --category="Features%%feat:" --category="Fixes%%fix:"

Considering the chances of %% being together in a regex being very rare and also since the logic would only take the first separation to get the LABEL everything else would be compiled back as regex.